Work holder for assembling a cathode ray tube envelope

ABSTRACT

A cathode ray tube envelope consisting of a neck portion, a funnel portion and a panel portion having a rectangular screen is assembled with reference to the round portion of the funnel portion. The cross section of the round portion is circular and accordingly the geometric center of the funnel portion can be detected easily.

United States Patent [19'] Adachi et a1.

[451 Apr. 23, 1974 1 WORK HOLDER FOR ASSEMBLING A CATHODE RAY TUBEENVELOPE [75] Inventors: Hiroshi Adachi, Yokohama;

Yoshihiro Tsukamura, Kawasaki, both of Japan [73] Assignee: SonyCorporation, Tokyo, Japan [22] Filed: Oct. 27, 1971 [21] App]. No.:192,816

[30] Foreign Application Priority Data Oct. 30, 1970 Japan 45-96239 [52]U.S. Cl 269/287, 29/25.l9, 269/321 T [51] Int. Cl B23q 3/00 [58] Fieldof Search 29/25.l3, 25.19, 25.2,

29/203 J, 203 P; 220/21 A; 316/], 27, 31; 65/58; 269/287, 305, 321 T[56] References Cited UNITED STATES PATENTS 3,329,422 7/1967 Hajduk269/287 3,369,881 2/1968 Bennett et al. 65/58 2,889,952 6/1959 Claypoole65/58 X 3,118,662 l/l964 Fassett et al.. 269/305 X 3,305,123 2/1967Nordby 220/21 A 5/l968- Reinwall, Jr. 220/21 A X Primary ExaminerRoyLake ssistq t ExaminerJ. W. Davie Attorney, Agent, or F irm-Hill,Sherman, Meroni, Gross and Simpson [5 7] ABSTRACT A cathode ray tubeenvelope consisting of a neck portion, a funnel portion and a panelportion having a rectangular screen is assembled with reference to theround portion of the funnel portion. The cross section of the roundportion is circular and accordingly the geometric'center of the funnelportion can be detected easily.

3 Claims, 3 Drawing Figures P/ m 7A A L Y MOUNTED PATENTED APR 2 3 I914SHEET 2 OF 2 INVENTORS YwHIHI/W HUM/4W1 M t JWATTORNEY WORK HOLDER FORASSEMBLING A CATI-IODE RAY TUBE ENVELOPE BACKGROUND OF THE INVENTION 1.Field of the Invention v a This invention relates to cathoderay tubeenvelopes, and more particularly to a method of the fabrication of colortelevision picture tube envelopes having a rectangular panel screen.

2. Description of the Prior Art Generally, glass cathode ray or colortelevision picture tube envelopes consist of a neck portion havingenclosed therein an electron gun, a funnel portion having wide andnarrow openings at opposite ends thereof and a viewing panel portionhaving formed thereon a phosphor screen and, if necessary, havingattached thereto a shadow mask, these portions being sealed together asby frit glass to form a completed tube envelope. In this case, the threeportions must be assembled together precisely in predeterminedrelationships to one another.

Namely, inaccurate assembling of the three portionscauses low purity,mislanding, misconvergence and so on, and hence is undesirable for thefabrication of color television receiving sets.

To avoid such a defect, various methods and apparatus for assemblingcathode ray or color television picture tube envelopes have heretoforebeen proposed but no satisfactory ones have been realized.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is toprovide an apparatus for assembling cathode ray tube envelopes withwhich it is possible to seal the neck, funnel and panel screen portionstogether as a unitary structure with these portions being preciselyaligned with one another.

Another object of this invention is to provide a .method for assemblingthe neck portion and/or panel screen portion with a funnel portion withreference to the round portion (defined later on) of the funnel portionof a tube envelope.

Another object of this invention is to provide a method for assemblingthe neck portion with the funnel portion of a tube envelope withreference to the round portion of the latter.

Another object of this invention is to provide a method for assemblingthe panel screen portion with the funnel portion of a tube envelope withreference to the round portion of the latter.

Another object of this invention is to provide a jig for inspection of acomposite funnel-neck article with reference to the round portion of thefunnel portion.

Still another object of this invention is to provide a novel method forassembling a cathode ray tube having a rectangular panel screen.

Other objects, features and advantages of this invention will becomeapparent from the following description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic diagram, forexplaining this invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding ofthis invention, a brief description will be given first of aconventional cathode ray tube envelope and a method of assembling it inconnection with FIG. 1. A neck portion 1 is sealed to a sealing end 2bof a funnel portion 2 with the geometric center axis X--X of the formerbeing aligned with that O of a sealing end 2a of the latter and a panelscreen portion 3 is sealed to the sealing end 2a of the funnel portion 2with the geometric center P being aligned with that O of the former,thus providing a composite article 4. Of course, the geometric centeraxis X--X of the neck portion 1 is selected perpendicu lar to thesealing end 2a of the funnel portion 2 and/or the viewing screen of thepanel screen portion 3. With such a conventional method, however, it isvery different precisely to find out the geometric center 0 of thesealing end 2a of the funnel portion 2. The present invention does notinvolve such detection of the geometric center of the sealing end 2a,and hence allows much ease in the fabrication of cathode ray tubeenvelopes.

In FIG. 2, reference numeral 5 indicates generally an apparatus or a jigfor assembling a cathode ray tube envelope. The apparatus 5 comprises afirst positioning means 8 for aligning the center of a round portion 13of a funnel portion 2 with the geometric center of a neck portion 1 and,preferably, a second positioning means 10 for aligning the geometriccenter P of a panel screen portion 3 with the extension YY of a linejoining the center of the first positioning means 8, that is, the roundportion 13 with the center of the neck portion 1.

The round portion 13 of the funnel portion 2 herein mentioned is onepart of the tubular portion of the funnel 2 which may include a smallopen end 2!) and on which a deflection coil assembly (not shown) ismounted and the round portion 13 substantially corresponds to the centerof electron beam deflection. This will be described a little more indetail. In a cathode ray tube having a rectangular panel screen,itssealing end 211 is naturally substantially rectangular but thesealing end 2b is circular, of course. Considering any given crosssections of the funnel 2 between, the two sealing ends thereof, thecross section of the funnel 2 is rectangular at its sealing end 2a butbecomes gradually round as the sealing end 2b is approached and trulycircular at the sealing end 2b. Here, the portion of the funnel 2 whereits crosssection becomes round is defined as a round portion in thisspecification. This round portion is used as a reference portion of thecathode ray tube according to this invention.

The first positioning means 8 consists of a circular, ring-shaped member6 for receiving the round portion 13 of the funnel 2 and, for example, apair of holders 7a and 7b extending downwardly thereof for holding thatportion of the neck portion 1 in which an electron gun is disposed. Atleast one of the holders 7a and 7b is formed integrally with thering-shaped member 6 and the other is pivotally mounted to the member 6for pressing the neck portion 1 to the one holder. Further, the firstpositioning means 8 is designed so that a line joining the center of thering-shaped member 6 with that of a circular space defined by arc-shapeddepressions of the both holders 7a and 7b may be aligned with a verticalline YY. Namely, by setting the neck portion 1 on the positioning means8, mounting the funnel 2 thereon and sealing them to each other, thecenter of the round portion 13 automatically coincides with the centerof the neck portion 1.

The second positioning means consists of an arm 16 extending upward fromthe ring-shaped member 6 and an L-shaped limit member 14 extendinglaterally from the upper end of the arm 16 to conform to two adjacentside walls of the rectangular panel screen portion 3. The L-shapedmember 14 carries two position adjusting screws A and 15B in its oneside and one position adjusting screw 15C in the other side.

These first and second positioning means 8 and 10 are supported by abase 9 secured to the ring-shaped member 6. The base 9 is made up ofthree base member 1 1a, 1 1b and 1 10 arranged, for example, in atriangular form and three supports 12a, 12b and 12c formed integrallytherewith. The first and second positioning means 8 and 10 and the base9 are formed of, for example, iron, as a unitary structure with oneanother as will be seen from the figure. The neck, funnel and panelscreen portions 1, 2 and 3 are placed one on another with the use of thejig 5 and placed, as they are, in a furnace to be sealed together withfrit glass to produce a completed cathode ray tube envelope. In thiscase, the neck, funnel and panel screen portions 1, 2 and 3 arepositioned as predetermined by the holders 7a and 7b, the ring-shapedmember 6 and the L-shaped limit member 14.

There are some occasions when the panel screen portion 3 is assembledwith a composite funnel-neck article by the use of the jig 5 shown inFIG. 2. In such a case, the composite funnel-neck article is mounted onthe jig 5. Since the ring-shaped member 6 and the holders 7a and 7b areconstructed as previously described, the extension connecting the centerof the neck portion 1 with that ofthe round portion 13 of the funnel 2coincides with the perpendicular YY which serves as the reference line.

Then, an examination is made as to whether the open end face of thefunnel 2 to be sealed to the panel screen portion 3, that is, theso-called sealing end 2a is perpendicular to the reference line YY. Thisexamination is achieved in such a manner as depicted in FIG. 3. Namely,a plurality of measuring points G G and G which abut against the sealingedge with the ringshaped member 6, that is, the round portion sealing 13being used as the reference, is provided in association with the jig 5and the gradient of the sealing edge 2a is measured from the amount ofdisplacement (height) of each of the measuring points 0,, G and G Whenthe sealing edge 20 is not perpendicular to the reference line YY, thesealing edge 2a is ground to be perpendicular to the line YY, then, thepanel screen portion 3 is placed on the funnel 2. At this time, by thepre-adjusted screws 15A, 15B and 15C of the second positioning means 10,the center P of the panel screen portion 3 is aligned with the referenceline YY and then the panel screen portion 3 is fixed to the funnel 2 bymeans of frit glass.

With the present invention described above, sealing of the funnel 2 tothe panel screen portion 3 is achieved using as a reference the lineconnecting the center axis of the neck portion 1 with the center of theround portion 13 of the funnel 2. This allows ease in aligning the axesof a deflection yoke magnetic field and an electron beam with each otherin the subsequent assembling of an electron gun and a deflection coilassembly with the tube envelope, thereby to facilitate assembling ofcathode ray tubes. Further, this invention does not necesitate detectionof the center of the sealing end 2a, so that assembling of the funnel 2with the panel screen portion 3 is easy.

As has been described above, the line connecting the axis of theelectron gun with the electron beam deflection center is used as thereference line, so that even if the funnel 2 and the neck portion 1 aresealed to each other a little out of position, the composite funnel-neckarticle can be used, with the result that yield of the cathode ray tubeenvelopes can be raised.

In the foregoing example the centers 0 and P of the round portion 13 ofthe funnel 2 and the panel screen portion 3 are aligned with thegeometric center axis XX of the neck portion 1 but the neck portion 1may be a little inclined to the panel screen portion 3 so long as theelectron gun and the panel screen portion 3 are. in' predeterminedalignment with each other. Namely, it is sufficient only to position thecenters 0 and P of the round portion 13 of the funnel 2 and the panelscreen portion 3 on the line passing through the center of any crosssection of the neck portion 1.

It willbe apparent that many modifications and variations may beeffected without departing from the scope of the novel concepts of thisinvention.

We claim as our invention:

1. A jig for assembling a cathode ray tube envelope formed of two joinedcomponent parts which include: a tubular neck part and a funnel parthaving a small end portion of circular cross section and a large endportion of generally rectangular cross section, said parts joinedtogether forming a portion of a cathode ray tube; said jig comprising aframe which includes at least a portion of an annular seat for receivingand seating said funnel part in. a region where its cross section iscircular, at least one arm in fixed relation to said annular seatlocated below said annular seat, said arm having receiv-, ing means forpositioning said neck part, said receiving means determining thelocation of the geometric center axis of said neck part, and saidannular seat determining the location of the geometric center of saidfunnel part in the plane of said annular seat, said geometric centerpoint of the funnel part intersected by the geometric center axis of theneck part.

2. A jig for assembling a cathode ray tube envelope formed of aplurality of component parts which include: a tubular neck part, afunnel part joined to said tubular neck part and having a small endportion of circular cross section and a large end portion of generallyrectangular cross section, and a rectangular panel part to form acathode ray tube envelope; said jig comprising a frame which includes atleast a portion of an annular seat for receiving and seating said funnelpart in a region where its cross section is circular, at least one armin fixed relation to said annular sea't located below said annular seat,said arm having receiving means for holding said neck part, anupstanding arm rigidly secured to said frame and having a fixed relationto said cation of the geometric center of said panel part in a secondplane parallel to said first plane, said geometric center axis passingthrough said geometric centers of said funnel part and said rectangularpanel part.

3. Ajig according to claim 1, in which a plurality of contacts areprovided to determine the perpendicularity of the edges of therectangular portion of the funnel part to the geometric center axis ofthe neck part.

1. A jig for assembling a cathode ray tube envelope formed of two joinedcomponent parts which include: a tubular neck part and a funnel parthaving a small end portion of circular cross section and a large endportion of generally rectangular cross section, said parts joinedtogether forming a portion of a cathode ray tube; said jig comprising aframe which includes at least a portion of an annular seat for receivingand seating said funnel part in a region where its cross section iscircular, at least one arm in fixed relation to said annular seatlocated below said annular seat, said arm having receiving means forpositioning said neck part, said receiving means determining thelocation of the geometric center axis of said neck part, and saidannular seat determining the location of the geometric center of saidfunnel part in the plane of said annular seat, said geometric centerpoint of the funnel part intersected by the geometric center axis of theneck part.
 2. A jig for assembling a cathode ray tube envelope formed ofa plurality of component parts which include: a tubular neck part, afunnel part joined to said tubular neck part and having a small endportion of circular cross section and a large end portion of generallyrectangular cross section, and a rectangular panel part to form acathode ray tube envelope; said jig comprising a frame which includes atleast a portion of an annular seat for receiving and seating said funnelpart in a region where its cross section is circular, at least one armin fixed relation to said annular seat located below said annular seat,said arm having receiving means for holding said neck part, anupstanding arm rigidly secured to said frame and having a fixed relationto said annular seat, said upstanding arm terminating in an L-shapedhorizontally extending flange which engages said panel part of aplurality of points, said receiving means determining the location ofthe geometric center axis of said neck part, said annular seatdetermining the location of the geometric center of said funnel part ina first plane determined by the plane of said annular seat perpendicularto the geometric center axis of said neck part, and said upstanding armdetermining the location of the geometric center of said panel part in asecond plane parallel to said first plane, said geometric center axispassing through said geometric centers of said funnel part and saidrectangular panel part.
 3. A jig according to claim 1, in which aplurality of contacts are provided to determine the perpendicularity ofthe edges of the rectangular portion of the funnel part to the geometriccenter axis of the neck part.